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Magnetic liquid metal (MLM) is a mixture of magnetic particles with gallium‐based liquid metals which utilizes an unconventional combination of fluidity, high thermal/electrical conductivity, biocompatibility, and magnetism. Recently, from materials to applications, studies on MLMs have drastically increased. Single or multiple MLMs can be precisely positioned or can act as a carrier for handling other objects. MLMs are also used in biomedical applications such as cancer treatment by hyperthermia and precision delivery of cancer drugs on tumors, or antibacterial coating which kills bacteria. In electronics applications, MLMs are used for magnetic field‐driven patterning of metallic lines, reconfigurable interconnects, electronic tattoos, and reconfigurable electromagnetic wave shielding. Phase change (solid/liquid) of MLMs adds another unique capability, morphing. A combination of innovations in the micro/nano robots and MLMs has huge potential to bring an unprecedented disruptive technology for a wide variety of applications including self‐morphing shape‐recovery robots, highly localized cancer treatment, and reconfigurable stealth/camouflage, among others. This article comprehensively reviews recent developments in MLMs from the materials to methods of preparation, locomotion of MLMs, their applications, and future outlooks. [ABSTRACT FROM AUTHOR]

A gallium‐based liquid metal patterning for paper‐based soft electronics is reported. A method is proposed that is rapid and straightforward liquid metal patterning on a printing paper using selective wetting properties obtained by lyophilic and lyophobic coating. The paper is coated with a lyophilic waterproof agent followed by a lyophobic printing toner with a desired pattern in an inverse pattern. Then a sponge roller soaked with liquid metal is rolled and filled into the exposed waterproof agent coating to create the desired pattern. It is believed that this is one of the most convenient yet quite versatile liquid metal patterning methods. The minimum line pattern width, spacing, and patternable angle are 50 μm, 200 μm, and 3°, respectively. To demonstrate versatility, a university symbol and a map shape are coated with liquid metal. The bending, folding, cutting, pasting, and burning of the light‐emitting diode circuit on paper is also demonstrated. Additionally, the deposition of 3 μm Parylene on top of the liquid metal pattern works as a passivation layer, and no damage is noticed when the liquid metal pattern on the paper is repeatedly folded and bent. Finally, a pressure sensor using the proposed method by measuring resistance is demonstrated. [ABSTRACT FROM AUTHOR]